Field of the Invention
The present invention relates to an ophthalmic apparatus, an image processing method, and a storage medium.
Description of the Related Art
When using a conventional fundus camera, an examiner aligns the eye to be examined while observing an image of the eye on a display unit. When performing this alignment, the examiner performs alignment first while observing an anterior ocular segment image of the eye to be examined and the pupil in a wide field of view and then performs alignment while observing a fundus image of the eye.
There is known a fundus camera which electronically enlarges an anterior ocular segment image to enlarge and observe an observation image when an operator observes an anterior ocular segment image (Japanese Patent Laid-Open No. 7-194546). In addition, as cameras for observing a fundus image, there are known a fundus camera (Japanese Patent Laid-Open No. 5-192299) which enlarges and displays the fundus image captured by a built-in monitor and a fundus camera (Japanese Patent Laid-Open No. 2010-148586) which enlarges and displays the central portion of a fundus image in focus operation for focusing.
There has recently been proposed a technique of mounting a general-purpose digital camera in the optical system of a fundus camera, capturing a fundus image by the image sensor mounted in the general-purpose digital camera, and displaying a captured fundus image on the display unit of the general-purpose digital camera. In addition, there is known a fundus camera among recent fundus cameras which is capable of imaging the anterior ocular segment as well as capturing a fundus image.
The display units mounted in many such general-purpose digital cameras, however, have small sizes. It is therefore difficult to align the eye to be examined by using an image of the eye displayed on the display unit of such a general-purpose digital camera. Deciding, in particular, a display magnification so as to facilitate alignment at the time of observation of a fundus image will reduce the size of an image at the time of anterior ocular observation depending on the optical design and the like. This makes it difficult to improve the accuracy of alignment of the anterior ocular segment. For this reason, switching from the anterior ocular observation mode to the fundus image observation mode will display a fundus image at a shifted position. It therefore takes much time to perform alignment.
Assume that the optical display magnification is increased at the time of anterior ocular observation to solve the above problem. In this case, since an image of the anterior ocular segment is displayed in a narrow range, it is difficult to grasp the positions of the anterior ocular segment and pupil of the eye to be examined, resulting in an increase in time to align the anterior ocular segment. In addition, increasing the optical display magnification will narrow the imaging range for the anterior ocular segment.
The present invention has been made in consideration of the above problem and provides a technique capable of facilitating alignment and focus adjustment with respect to the eye to be examined by displaying an observation image at a proper display magnification for each observation state.